package model;

import com.mysql.jdbc.jdbc2.optional.MysqlDataSource;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

// 封装建立连接和关闭连接的操作
public class DBUtil { // 懒汉式
    private volatile static DataSource dataSource = null;
    private static DataSource getDataSource(){
        if(dataSource == null) {
            synchronized (DBUtil.class) {
                if (dataSource == null) {
                    dataSource = new MysqlDataSource();
                    ((MysqlDataSource) dataSource).setUrl("jdbc:mysql://127.0.0.1:3306/blog_system?characterEncoding=utf8&useSSL=false");
                    ((MysqlDataSource) dataSource).setUser("root");
                    ((MysqlDataSource) dataSource).setPassword("702908");
                }
            }
        }
        return dataSource;
    }
    public static Connection getConnection() throws SQLException {
        return getDataSource().getConnection();
    }
    public static void close(Connection connection, PreparedStatement statement,
                             ResultSet resultSet){
        if(resultSet != null){
            try {
                resultSet.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if(statement != null){
            try {
                statement.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if(connection != null){
            try {
                connection.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}
